I have both a 7" and a 10". Two 7" tablet, actually. A BB Playbook, Nexus 7 2013and a Lumia 2520. I bought them for different reasons, though.
The Playbook was the only one I actually set out to purchase. It was my first tablet. The Nexus 7 2013 was kinda of spur of the moment thing. I got annoyed with WP App support and decided I needed either an Android or iOS device. A tablet made sense. Had a line on a used iPad Mini (non retina) but it was just out of my budget, then. Decided $149 for the Nexus was a steal for what you get. Solid power, beautiful 1080p screen, fastest updates from Google, long support. Lots to like. Then, I stumbled upon the Lumia 2520 deal. Ideally, I wanted a non RT device, but I couldn't pass this up. $99 with an AT&T contract, which I had a phone line with. Wasn't the best deal, long term, but I don't mind $10 month and $99 upfront with the option for LTE usage.
I usually grab my 10" Lumia, at home. The large screen is really nice. I really only grab my Android if I need to use an Android App or I'm taking a tablet on the road. I did install Flash on my Nexus, and it works through Firefox, so I still have all tablets capable of playing Flash if need be. It's just nice to have the option... And I actually like Android 5.0! I don't necessarily prefer Win RT.
The Playbook has been a dedicated Slacker radio player at my work for months, and I rarely touched it even before that. Never got updates, somewhat slow, etc... It was basically only a browser that was Flash capable. No other benefit.
I see these deals for new 8" tablets with full Windows 8.1 for $150 and under (even $79!) and it's so tempting! I'd love a Win 8.1 (non RT) tablet. For nothing else than being able to use Nokia/Microsoft WP programs to install firmware on phones and such. I don't need a 4th tablet though... Lol. Bad thing about buying these inexpensive tablets is they have basically zero resale value.
Edit- Did not even realize this was posted in the specific Dell Stream forum. Lol. Bad thing about browsing from an App... Somewhat relevant reply, regardless.